MX2014006911A

MX2014006911A - Tire load sensing system.

Info

Publication number: MX2014006911A
Application number: MX2014006911A
Authority: MX
Inventors: Steven A Duppong; Bruce L Upchurch
Original assignee: Deere & Co
Priority date: 2013-07-29
Filing date: 2014-06-09
Publication date: 2015-01-28
Also published as: BR102014018258B1; CA2856911A1; EP2832561B1; US20150032287A1; US9085203B2; JP2015028477A; IN2014MU01813A; BR102014018258A2; EP2832561A1

Abstract

A vehicle tire load sensing system includes distance sensors mounted on the vehicle near each tire. The distance sensors generate distance signals representing a distance from the sensor to a track that is left in the soil during forward vehicle travel. Pressure sensors generate tire pressure signals. A temperature sensor senses the ambient temperature. A control unit receives the distance signals, the pressure signals and the temperature signals. The control unit compensates the distance signals as a function of the sensed temperature. The control unit generates filtered distance signals, and determines a tire deflection value from the filtered distance signal. The control unit determines the tire load as a function of the tire deflection value, the pressure signal and stored information relating tire load to tire deflection and tire pressure.

Description

SYSTEM. LOAD SENSOR. OF RIM Field of the Invention The present description relates to a tire load sensing system.

Background of the Invention It is desirable to measure or perceive the dynamic load on the tires of a tractor. Such information can be used to help automate a tire inflation system so that such a system can automatically change tire pressure in response to axle load conditions. Such information may be used in an agricultural front end loader or for construction to determine the amount of weight that has been collected by the loader. Such information can be used as a flat tire or flat tire detection system, or it can be used to determine the axle loads on the trailer systems.

Synthesis According to one aspect of the present disclosure, a tire load perception system is provided for a vehicle having tires which support the vehicle on a surface. The tire load perception system includes distance sensors mounted on the vehicle near each tire. Distance sensors generate distance signals that represent a distance from the sensor to the surface.

The distance sensors are preferably conventional ultrasonic distance sensors, and are directed to the compressed footprint left in the ground during forward movement of the vehicle. Pressure sensors generate tire pressure signals. A temperature sensor senses the ambient temperature. A control unit receives the distance signals, the pressure signals and the temperature signals. The control unit compensates the distance signals as a function of the perceived temperature. The control unit generates the filtered distance signals, and determines a tire deflection value of the filtered distance signal. The control unit determines the tire load as a function of the tire deflection value, the pressure signal and the information stored in relation to the tire load for tire deflection and rim pressure.

Brief Description of the Drawings Figure 1 is a schematic and simplified side view of a vehicle with ultrasonic distance sensors and having fully inflated tires; Figure 2 is a simplified schematic side view of a vehicle with ultrasonic distance sensors and having partially deflated tires.

Figure 3 is a schematic block diagram of a signal processing system which processes the signals from the sensors of Figures 1 and 2; Y Figure 4 is a flow diagram of an algorithm performed by the electronic control unit of Figure 3.

Detailed Description of the Drawings Referring to Figure 1, a vehicle 10 has the fully inflated front and rear tires 12 and 14 which rest on a surface 16. A distance sensor 18a is mounted on the vehicle near the left front tire 12 and at a distance Al above. of the surface 16. A distance sensor 20a is mounted on the vehicle near the left rear tire 14 and at a distance Bl above the surface 16.

Figure 2 is similar to Figure 1 except that the tires 12 and 14 are partially deflated so that the distance sensor 18b is at a smaller distance A2 above the surface 16, and the distance sensor 20b is at a distance smaller B2 above the surface 16. The distance sensors 18 and 20 are preferably conventional ultrasonic distance sensors, and these are mounted on the tractor frame such that the field of view of each sensor is looking behind the corresponding rim with respect to the direction of normal forward movement of the tractor 10. Therefore, the sensors 18 and 20 will perceive the distance to the compressed footprint that is left in the ground during the movement of the vehicle forward. This provides a consistent target surface relative to the axis of the tractor 10.

The distance sensors can be placed inside the rims on the rims and measure the deflection from the inside of the rim and transmit the data to the vehicle controller through a wireless data link. The distance sensor can also be mounted on the tractor front and rear axles to detect subtle changes in distance from the axle to the ground based on tire pressure.

Referring now to Figure 3, the signal processing system includes the left and right front distance sensors 18a and 18b, and the left and right rear distance sensors 20a and 20b. The distance sensors 18a, 18b, 20a and 20b are preferably commercially available ultrasonic distance sensors. The pressure sensors 22a-22d perceive the pressure of each of the corresponding rims. A temperature sensor 24 senses the ambient temperature and is preferably located on the frame of the tractor 10. The perceived temperature is used to compensate the ultrasonic distance signals from the sensors 18 and 20.

An electronic control unit (ECU) 30 is connected to receive the signals from all sensors 18, 20, 22 and 24. The electronic control unit 30 processes the sensor signals and generates a tire load output signal by executing an algorithm 100 represented by FIG. 4. The firing charge output signal is displayed on a conventional display 32 at an operator station (not shown) on the tractor 10. The conversion of the flow scheme into a standard language to implement the algorithm described by the flow scheme in a computer or digital microprocessor will be evident to one with ordinary skill in the art.

In step 102 the electronic control unit 30 obtains the raw distance data from the distance sensors 18a, 18b, 20a and 20b.

In step 104, the electronic control unit 30 reads the tire pressure sensors and the temperature sensor 24.

In step 106 the electronic control unit 30 calculates and compensates the distance data based on the perceived temperature.

In step 108 the offset distance values are filtered using a running average method.

In step 110, an off-center value is subtracted based on the sensor height from the distance values to obtain the deflection or rim radius values.

In step 112 the load values are obtained by placing the values of tire deflection and rim pressure perceived inside a stored look table containing the tire deflection values at known pressures, based on the information published by the tire manufacturers. An example of such a table is illustrated by Figure 5.

The electronic control unit 30 can also, in response to changes in the determined load values, generate the pressure adjustment values which can be used by the tire inflation system (not shown) to adjust the tire pressures to the pressures desired.

Although the description has been illustrated and described in detail in the drawings and the foregoing description, such illustration and description should be considered as an example and not as a restriction in character, it being understood that illustrative embodiments have shown and described that all changes and modifications that fall within the spirit of the description are desired to be protected. It will be noted that the alternate embodiments of the present disclosure may not include all of the features described but still benefit from at least some of the advantages of such features. Those of ordinary skill in the art will be able to easily design their own implementations that incorporate one or more of the features of the present disclosure and which fall within the spirit and scope of the present invention as defined by the appended claims.

Claims

R E I V I N D I C A C I O N S

1. In a vehicle having rims which support the vehicle on a surface, a tire load perception system comprising: a distance sensor mounted on the vehicle and generating a distance signal representing a distance from the sensor to the surface; a pressure sensor to generate a tire pressure signal; Y a control unit which receives the distance signal and the pressure signal, the control unit generates a filtered distance signal, the control unit determines a tire deflection value from the filtered distance signal, and the control unit The control determines the tire load as a function of the tire deflection value, the pressure signal and the information stored in relation to the tire load for tire deflection and rim pressure.

2. The rim load perception system as claimed in clause 1, further characterized because it comprises: a temperature sensor to sense the ambient temperature, the control unit compensates the distance signals as a function of the perceived temperature.

3. The rim load perception system as claimed in clause 1, characterized in that: The distance sensor comprises an ultrasonic distance sensor mounted on one side of the rim.

4. In a vehicle having a plurality of rims which support the vehicle on a surface, a rim load perception system comprising: a plurality of distance sensors, each mounted on the vehicle to one side of a corresponding one of the rims and each generating a distance signal representing a distance from the sensor to the surface; a plurality of pressure sensors each for generating a tire pressure signal for a corresponding one of the rims; Y a control unit which receives the distance signals and the pressure signals, the control unit generates a filtered distance signal for each tire, the control unit determines a tire deflection value from each filtered distance signal, and the control unit determines the tire load values as a function of the tire deflection values, the pressure signals and the information stored in relation to the tire load at the tire deflection and the rim pressure.

5. The rim load perception system as claimed in clause 4, characterized in that it comprises a temperature sensor for sensing the ambient temperature, the control unit compensates the distance signals as a function of the perceived temperature.

6. The rim load perception system as claimed in clause 4, characterized in that: The distance sensor comprises an ultrasonic distance sensor mounted on one side of the rim. SUMMARY A vehicle tire load sensing system includes distance sensors mounted on a vehicle near each tire. The distance sensors generate the distance signals by representing a distance from the sensor to a footprint that is left in the ground during the movement of the vehicle forward. The pressure sensors generate tire pressure signals. A temperature sensor senses the ambient temperature. A control unit receives the distance signals, the pressure signals and the temperature signals. The control unit understands the distance signals as a function of the perceived temperature. The control unit generates the filtered distance signals and determines a tire deflection value from the filtered distance signal. The control unit determines the tire load as a function of the tire deflection value, the pressure signal and the information stored in relation to the tire load at the tire deflection and at the rim pressure.